Description

S-(+)-4-methyl-3-hetanone has been identified as the principal alarm pheromone of Atta texana and Atta cephalotes. Both enantiomers of 4-methyl-3-heptanone have been synthesized and their biological activities have been compared on both species of ants. Comparison of the geometric averages of responnse rations, at threshold concentration levels on A. texana, showed S-(+)-4-methyl-3-heptanone to be about 100 times more active than the (-)(+)-4-methyl-3-heptanone by the (-) enantiomer. A less rigorous study on A. cephalotes shoes S-(+)-4-methyl-3-heptanone.

Both ant species produce 3-octanone, possible trace amounts of 3-octanol, and both diasteremoers of 4-methyl-3-heptanol. A. texana also produces (+)-2-heptanol, 2-heptanone, and 3-heptanol. A. cephaloteS contains trace amounts of 2-heptanone.